Buckaroo's Flightgear Projects
Guide To YASim: Contents

About this YASim Guide

This guide is the result of years of working intensely with YASim. I started knowing not much, and anyone flying some of my early efforts will need more than a wing and a prayer. But gradually I learned more, from studying the FDMs of others, my own trials and errors, the many comments on the Flightgear forums, digging deep into developer list archives, and long hours working through the code, often working numbers through the algorithms by hand to see what they do. I ended up learning a lot more than I expected. My understanding of what keeps a plane in the air is vastly greater than it was when I began working with Flightgear FDMs.

I can't say I understand all there is to know about YASim, far from it, so I can't guarantee that this guide has no errors or wrong interpretations. It probably has many. But I try to write about things for which I have direct experience. An observant reader will find gaps, and those gaps are likely areas where I have no experience or where I don't yet feel confident in my understanding.

I regret that the guide will not be very useful to rotary-wing enthusiasts. I began using Flightgear by flying helicopters-- it was a novelty because at the time no other simulator had a good helicopter flight model. But my focus shifted to fixed-wings, and I currently have no experience with rotary-wing FDMs. Maybe someday...

I hope those working with Flightgear get something from this guide. It took a long time to assemble, and there's work still to be done. I welcome thoughts, suggestions for additions, and corrections.

Copyright, Copying, Etc.

All portions of this guide are my work, and the guide is copyrighted by me, all rights reserved. That said, permission is granted to use small portions of this guide in other works, so long as those portions are not altered and are clearly attributed to me.

I believe a French translation of this guide is in progress, but probably won't be completed for some time.


This guide is dedicated to the Flightgear community, and especially to those who have helped me in the past, flight tested my modeling efforts, encouraged me, or flown with me on those long, laid-back flights from here to there in the virtual Flightgear world. These folks include but are not limited to Peter "Farmboy" Brown, Lanny "Someguy" Chambers, Wolfram "Yakko" Gottfried, Syd Adams, Jacob "Tuxklok" Burbach, Emmanuel "Helijah" Baranger, Jörg "Jomo" Emmerich and quite a few others who it's been my honor to know and work with.

-Gary "Buckaroo" Neely

Contact me as "Buckaroo" on the Flightgear forums or as grneely on Google's gmail service